Failed to save MyProject.xcodeproj. Unknown error.

I was developing this application from a year and working
every day wth it.


Updated to the new XCode Version 7.3.


When I tried to save and exit XCode, got this error:

Failed to save MyProject.xcodeproj. Unknown error.


Then tried to change and save another file and got an error:


The document *** could not be saved, You don't have

permission.


I do have read/write permissions.


I can build and install on device.


Tried to exit again. Got the same error.


Also when I try to create new project with my Team ID.

Can build and install on device but when try to exit got the same error - cannot save it.